Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (04): 759-763.doi: 10.3866/PKU.WHXB20110415

• Communication • Previous Articles     Next Articles

Electrodeposition and Electrochemical Property of Porous Li-Si Film Anodes for Lithium-Ion Batteries

Lü Rong-Guan, YANG Jun, WANG Jiu-Lin, NULI Yan-Na   

  1. School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
  • Received:2010-12-13 Revised:2011-02-17 Published:2011-03-29
  • Contact: YANG Jun E-mail:yangj723@sjtu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20873085).

Abstract:

Porous Li-Si thin films (LSFs) were prepared by a multi-step constant current electrodeposition onto Cu foil. The structure and morphology of the electrodeposited films were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). As anodes for Li-ion batteries, Li-Si films give high cycling stability, adjustable Li-storage capacity and initial coulombic efficiency under different electrodeposition conditions. For instance, LSF-3 was electrodeposited in an electrolyte of 0.5 mol·L-1 SiCl4+0.7 mol·L-1 LiClO4+propylene caronate (PC) under certain conditions (i1=-3.82 mA·cm-2, t1=600 s; i2=-1.27 mA·cm-2, t2=7200 s). LSF-3 showed the first coulombic efficiency of 97.1% at a current density of 12.7 μA·cm-2. After the two initial pre-cycles, it delivered gravimetric and geometric charge capacities of 1410 mAh·g-1 and 240.6 μAh·cm-2 at 25.5 μA·cm-2. After 50 cycles, its charge capacity was 179.0 μAh·cm-2 (1049 mAh·g-1), retaining 74.4% of its initial capacity. The porous structure in LSFs can accommodate a part of the volume change during Li insertion/extraction and this favors the structural stability.

Key words: Porous Li-Si film, Electrodeposition, Coulombic efficiency, Anode material, Lithium-ion battery

MSC2000: 

  • O646